A typical female molly would have anywhere between 10 and 140 babies after a gestation period of around 28 to 60 days. Larger and mature females usually produce more babies and warmer temperatures speed up the gestation period.
Mollies are extremely common among aquarium owners for a myriad of reasons. These fish are calm, remarkably hardy, and reproduce quickly. Combine that with the beautiful colors of their species, and you get a perfect fish for your tank.
In today’s article, we’ll take a closer look at the reproduction cycle of mollies and how to care for the babies in order to have a thriving population of mollies in your tank. Let’s dive right in!
How Many Babies Do Mollies Have?
Unlike many fish that lay eggs, mollies are livebearer fish. This means that, instead of laying the eggs somewhere safe, the female will keep the eggs inside its body throughout the gestation period and give birth to live young, usually called fry.
You should expect a female molly to have as little as 10 live babies and up to 140. In some rare cases, the number of babies may even surpass 200 fry.
Among the main factors that affect the number of babies born is the size of the female and its level of maturity as well as the conditions during the gestation period. This includes proper nutrition, temperature, water hardness, acidity, and so on.
How Long Is the Gestation Period of Mollies?
Similar to the number of babies born, the gestation period of mollies can vary. In some species, female mollies can gestate their young for as little as 4 weeks.
On the other hand, species like the Dalmation molly have a longer gestation period that extends beyond 60 days.
However, it’s noticeable that the babies born after a long gestation period are usually more mature than the ones birthed early and may not even require separation during early days, but more about that in the following sections.
How Do You Encourage Mollies to Breed?
Mollies are known for their high affinity for breeding, even when they are in captivity. For that reason, all you have to do in order to encourage mollies to breed is to increase their protein rations and keep the water temperature slightly warm (around 75 to 80 degrees F)
However, you might want to keep about 2 males for every female in the tank in order to reduce aggression between males.
Can Mollies Breed Without Males?
A popular misconception about mollies is that a female can give birth without males. Some people think so because female mollies may start giving birth multiple times even after being separated in a tank.
What happens here is that females are capable of storing the sperm of a male for several months, which allows the female to give birth multiple times with gestation periods in between, all from mating with a male once.
How to Tell if a Molly is Pregnant?
There are multiple ways to tell that a molly is pregnant. At first, the behavioral changes are a clear sign of the beginning of the gestational period.
During that time, the fish will be noticeably less active and isolate itself from other fishes in the tank. You’ll also notice that the fish often swim around the heater to get more warmth.
When a molly starts storing eggs inside its body, its belly will also start to swell, which is a clear sign of pregnancy and that the fish is about to give birth soon.
Do Mollies Eat Their Fry?
Like many other fish species, mollies will eat their fry. As soon as you notice that your female is close to her labor day, you should make sure to transfer her to a separate tank in order to protect the young from other fishes in the tank or at least keep her in a breeding box inside the tank.
Once the mother gives birth to her babies, it may start feeding on them as a quick source of nutrition, which is why you should return the mother to her original fish tank immediately after birth.
Some aquarium owners like to let the mother eat a few babies to provide the mother with nutrition and allow the fastest and healthiest babies to survive by hiding between plants.
How to Care for the Baby Mollies?
After removing the female from the nursing aquarium, you allow the babies to grow to a suitable size so that they’re big enough to not be eaten by other fish in your fish tank.
You can feed baby mollies anything from ground flakes and small worms all the way to baby shrimp eggs.
Remember to also optimize the tank so that it’s warm to let the fry grow (about 70 to 83 degrees F). You’ll also need to optimize the pH of the tank between 7.0 to 8.5.
How Do Baby Mollies Look Like When They’re Just Out?
When baby mollies are first born, they’re extremely tiny when compared to the mature molly. The juvenile fry usually has a teardrop shape with a small tail with two dark eyes and a transparent body with some coloration (usually orange).
Within the first few weeks, the fry starts to develop into small sized molly fish. After about 3 to 4 months, the fry will get their color, depending on the species of their parents.
This wraps it up for today’s guide that walks you through everything you need to know regarding the reproduction cycle of mollies and how to care for the young fry.
As you can see, a typical female molly should produce anywhere between 10 to 140 fry after a gestation period of about 28 to 60 days.
The numbers vary according to the size of the female as well as the temperature of the fish tank during the gestation period.